customcutter
11-12-2014, 06:23 PM
I bought a new (very old) stock ABB ACS 311-4P1-1 VFD to go on the mill I've been converting to CNC for a couple of years now.
I thought I would hire an electrician to wire it because I don't know a lot about electrical, usually just enough to get me into trouble. I contacted a friend with an electrical company, he said yes I've got an electrician that has wired a few VFD's. He came over and started wiring everything up, and I told him that I had read/heard that you shouldn't have any type of switches between the VFD and motor, and if you do definetly don't switch anything with the VFD under power. He said he had never heard of such a thing, but put the switch in low speed forward position on the mill. He finished wiring the VFD switched on the power and started programming the VFD. He could get it to run at about 15 RPM's and when he would shut it down and restart it, then it would run at around 1725 RPM's. Each time he would start/stop the mill from the VFD it would switch between RPM's of 15 or 1725. I couldn't see what he was programming into the VFD, but he finally reached over and moved the switch on the mill while power was on the VFD. This all happened on monday, I've been searching the internet, read the owners manual at least 15-20 times. Programmed it probably 30 times. All it would do since he flipped the switches is the motor would emit a high pitch whine when power was sent to the motor. I finally broke down today and called ABB tech support. He told me to get voltage readings with the motor disconnected, then reconnect the motor and get voltage and amp readings on each leg. Turns out the U2 lead is only reading .4amps, and the other 2 motor leads are reading 14amps each. I called tech support back and he said the VFD is toast, parts aren't even available for it.
I don't know if the elec toasted it, or it just happened. I guess I'll start looking on Fleabay, got the last one off of CL locally, no warranty.
thanks for letting me vent, saved the wife an ear full.
CC
I thought I would hire an electrician to wire it because I don't know a lot about electrical, usually just enough to get me into trouble. I contacted a friend with an electrical company, he said yes I've got an electrician that has wired a few VFD's. He came over and started wiring everything up, and I told him that I had read/heard that you shouldn't have any type of switches between the VFD and motor, and if you do definetly don't switch anything with the VFD under power. He said he had never heard of such a thing, but put the switch in low speed forward position on the mill. He finished wiring the VFD switched on the power and started programming the VFD. He could get it to run at about 15 RPM's and when he would shut it down and restart it, then it would run at around 1725 RPM's. Each time he would start/stop the mill from the VFD it would switch between RPM's of 15 or 1725. I couldn't see what he was programming into the VFD, but he finally reached over and moved the switch on the mill while power was on the VFD. This all happened on monday, I've been searching the internet, read the owners manual at least 15-20 times. Programmed it probably 30 times. All it would do since he flipped the switches is the motor would emit a high pitch whine when power was sent to the motor. I finally broke down today and called ABB tech support. He told me to get voltage readings with the motor disconnected, then reconnect the motor and get voltage and amp readings on each leg. Turns out the U2 lead is only reading .4amps, and the other 2 motor leads are reading 14amps each. I called tech support back and he said the VFD is toast, parts aren't even available for it.
I don't know if the elec toasted it, or it just happened. I guess I'll start looking on Fleabay, got the last one off of CL locally, no warranty.
thanks for letting me vent, saved the wife an ear full.
CC